Many programs in the K-12 education crisis in the US aim to raise 'the' levels of achievement of kids in our way-behind school systems. The idea is that to be 'competitive', the US needs to regain some quality edge in general education, and that for various reasons we've been falling way behind other nations.
Now a study asks whether by doing this highly democratic act, we are actually undermining ourselves. By our No Child Left Behind, teach to the test, include all policy, we are damping the learning and advantages that our sharpest kids have, that is in a sense just the opposite of what 'competitiveness' demands.
In universities, the grab for tuition takes the form of increased enrollments, grade inflation, faculty size reduction, class size increases, and reluctance to fail students who really don't belong (intellectually) in serious colleges or universities. We see it here in stark ways at Penn State, but it's a general problem (even, to some extent, in the elites, with their grade inflation). When we admit more students, dare not fail them because we need their tuition to pay our salaries (that is, of the faculty, so we can do 'research' while instructors with no tenure and lower pay do the teaching), then we are watering down classes. Penn State is as usual part of the crowd, not taking a lead in setting a higher standard, which means that while we're part of the problem we're not particularly culpable. We like most universities pay too much attention to student course evaluations, turning faculty into entertainers who don't make courses too difficult or assignments too long.
The result is that we make classes passable by students who really would be better served at less research-intense, less ambitious universities. We water things down and the main victims are the really smart and serious students, who are here in substantial numbers as we can personally attest. That's because they deserve much more than watered-down courses. They deserve, and can handle, much more rigorous courses. We don't mean just 'hard' courses or poorer grades, but simply courses that present more sophisticated material.
If we dumb down and thereby cheat the students in K-12 and then continue the process at the college and university level, naturally what we get at the end of the pipeline are people less well trained than they could be, and nobody is more affected in this way than the very best students.